Heat motor



'R/M. scHuL'rz HEAT MOTOR Filed Marchy 9 I&\\\\\\\\\\\\\\\\\ Aug. 27, 1935.

Patented Aug. 27, 1935 UNITED STATES PATENT OFFICE HEAT MOTOR of Illinois Application March 9, 1932, Serial No. 597,739

11 Claims.

. My invention relates yto a vapor motor, and more particularly to a type of vapor motor having volatile liquid therein adapted to expand by a variation of temperature whereby to expand the motor and actuate the control device or devices to which the motor is connected.

In a vapor motor of this type, it is preferable to eliminate air spaces by substantially filling the closed vessel with the volatile fluid. In copending application, Serial No. 366,933, filed May 29, 1929, and now issued as United States Letters Patent No. 1,885,285, it is pointed out that such air spaces tend to cushion the expanding action and destroy a positive movement.l The initial pressure developed by volatilization of the liquid compresses the air instead of expanding the vessel.

I have further found that air in the presence of the volatile liquid undergoing constant thermal expansion and contraction causes chemical reactions tending to' liberate free gas, which, when combined with the air, will enlarge the air spaces and will thereby affect the return movement of the vessel. Further chemical destruction of the fiuid has been also found to follow with the result that the Vapor motor would soon lose its positive action, -its predetermined stroke and its power.

If, on the other hand, the air spaces are omitted and the motor is completely filled with the volatile liquid, a very peculiar jumping action will occur upon initial expansion shortly after the heat is applied. It is well known that the molecules of a body of liquid undergo continuous bombardment, by one another, and that, witha rise of temperature, this bombardment increases until the velocity causes escape of the molecules, particularly at the surface. But with the vessel completely lled with volatile iiuid, escape of the molecules at the surface is prevented to the extent that the bombarding action continues so violently within the vessel that the molecules having the greatest velocity suddenly accumulate in a group to free themselves and cause a sudden jumping of the motor. Thus the initial expanding action is delayed, and when it does occur, it acts so suddenly and violently that the use of the motor becomes somewhat objectionable in certain cases.

I have discovered that this initial jumping action of the motor may be overcome, without requiring the presence of air spaces, by forming a vacuum pocket above the volatile liquid during the assembly of the motor. This is accomplished by extending, or .slightly drawing, the movable end of the motor outwardly and holding it in this position by a stop on the actuating arm.

By means of this arrangement, the initial rise of temperature and increased molecular activity of the liquid may produce immediate vaporization and immediate resultant pressure to effect a quick but smooth expanding action of the motor. In order to instruct those skilledin the art how to construct and practice my invention, I shall now describe a preferred embodiment thereof, in connection with the accompanying drawing which forms a part hereof.

In the drawing: Figure 1 is a vertical sectional view of a vapor motor;

Fig. 2 is a similar view of the vsame vapor motor embodying my invention; and

Fig. 3 is an alternative embodiment of my invention. l

In the drawing, wherein, for purposes of illustation, there is shown a preferred embodiment of 'my invention, the vapor heat motor may com- 20 prise an expansible and contractible vessel 5 having a volatile fluid 6 therein, such as benzol, toluene, or other suitable liquid, and a suitable source of heat for the volatile liquid, which, in this case, may be carried by a tube l in communication with'vessel 5. v

Although any suitable form of'expansible and contractiblevessel may be employed, it is preferably shown as comprising an inverted rigid cup8 and an expansible and contractible wall 9. In the particular form shown in the drawing, expansible and contractible wall 9 may be a well-known A form of bellow arranged in nested relation with respect to cup 8 and hermetically sealed at I0 to a rim plate in the form of a ring Il, to which cup 8 is also hermetically sealed. The arrangement provides a closed liquid chamber I2.

Tube 1 may be closed at either end and communicate at the opposite endwith chamber l2. As to the specific form of heatingdevice that may 40 be used, it is obvious that thesource may be an electric resistance coil or heating flame (not shown) conveniently located at or adjacent to tube 1. A heating zone will thereby be provided within tube 'l for heating volatile liquid 6. 'I'he 45 vapor pressure will be gradually increased until the liquid is driven out of theV heating zone and depressed into chamber I2. It is by this means that a predetermined expansion or power stroke of vessel 5 may be effectively obtained and held 50 without danger of the vapor pressure building up to a point where vessel 5 will burst. y

A heating element Il, which, in this particular instance, isin the form of an electric resistance coil, suitably surrounds tube 1. This coil is,` of

of said portion which is'vaporized by said source of heat whereby to overcome a; jumping action of said chamber upon initial vaporization of the fluid and expansion of said chamber when said source of heat is energized.

` 2. A heat motor comprising, in' combination, an expansible and contractible chamber and a volatile fluid therein to form a substantially closed volatile fluid therein to form a substantially closed uid lled system, a source of heat associated with said chamber to provide a heating zone for the fluid whereby to vaporize apart ofthe fluid and create a pressure expanding said chamber, and means for preventing a jumping action upon initial expansion of said chamber when said source of heat is energized, said means providing a free surface for the fluid at said heating zone for initial vaporization.

4. A heat motor comprising, in combination, an expansible and contractible chamber and a volatile fluid therein to form a substantially closed fluid filled system, a resistance associated with said chamber and a source of electric energy in circuit with said resistance to provide a. heating zone for the iiuid whereby to vaporize a part of the uid and create a pressure expanding said chamber, and means for preventing a jumping action upon expansion of said chamber when said resistance is energized, said means providing a free surface for the fluid substantially at said heating zone for initial vaporization.

5. A heat motor comprising, in combination, a substantially closed vessel having a movable part 4and a relatively immovable part, a volatile liquid substantially completely lling said vessel, a. source of heat for said liquid, an actuating arm secured to said movable part, and an abutment on Isaid actuating arm holding said actuating arm and said movable part in a permanently xed extended position to provide a free surface within said vessel for said volatile liquid.

6. Aheat motor comprising, in combination, an expansible work chamber, a volatile fluid in said chamber, and a heating zone for the fiuid, said work chamber and said heating zone forming a substantially closed uid filled system, a source of heat for the uid in said heating zone whereby to vaporize at leastla part of the fluid in said heating zone and create a pressure expanding said chamber, and means for holding said work chamber extended to provide a free surface for the iiuid in said heating zone whereby to provide for initial vaporization of the uid at said free surface and overcome an initial jumping action thereby when said source of heat is energized.

7. A heat motor comprising, in combination, an expansible work chamber, a volatile uid in said chamber, and a heating zone for the iiuid, said work chamber and said heating zone forming a substantially closed fluid filled system, a resistance associated with said heating zone and a source of electric energy in circuit with said resistance whereby vto vaporize at least a part of the iluid in said heating zone and createapressure` expanding said chamber, and means for holding said'work chamber extended to provide a free surface for the iiuid in said heating zone whereby to provide for initial vaporization of the fluid at said free surface and overcome an initial jumping action thereby when said resistance is energized.

8. A heat motor comprising, in combination, an expansible work chamber and a volatile fluid -in said vchamber to form a substantially closed fluid iilledsystem, including a heating zone as a part thereof, a source of heat for the fluid in said heating zone whereby to vaporize at least a portion oi the iluid therein and create a pressure expanding said chamber, and means for lowering the liquid in said heating zone to provide a fixed level therefor whereby to confine the initial vaporization at said level and overcome jumping' of said chamber upon initial expansion thereof. I

9. A heat motor comprising, in, combination,

' a closed expansible and contractible vessel substantially completely filled with a volatile liquid, a source of heat to volatize said liquid, and a plurality oi' fragmentary porous particles secured to the interior of said vessel at the point of initial vaporization of said liquid to prevent sudden expansion of said liquid and a consequent jumping of said vessel uponinitial expansion.

10. In a heat motor, a closed system including a work chamberA and a communicating heating chamber positioned to collect vapors formed within said system, a uid within said system substantially completely filling said chambers when introduced, a heating element associated with said heating chamber to heat a'limited amount of said fluid in said heating chamber and volatilize the same, thereby driving the unvolatilized uid in a direction out of said heating chamber into said work chamber, and means for overcoming an initial jumping action of said work chamber when heat is applied by holding said work chamber extended beyond its normal position of rest so as to lower said liquid at the top of said heating chamber and provide thereby a free surface expansible chamber expanded beyond its normal Y position of rest so as to lower said liquid at said upper portion and provide a free surface therefor.

ROY M. SCHULTZ. 

